Prospective memory is defined as remembering to perform an action in the future, such as remembering to give a friend a message or to make a doctor's appointment. The ability to perform prospective memory is essential for living independently as we age. For instance, a person who cannot remember to take medication or to turn off the stove will require daily assistance. Older adults often have more difficulty than younger adults with prospective memory. Understanding how the processes underlying prospective memory might differ in younger and older adults is essential for preventing decline and for creating useful techniques for compensating for those individuals who are having difficulty with this everyday memory task. The proposed research uses mathematical modeling techniques to test theoretically derived hypotheses about the relationship between age-related differences in executive control and age differences in prospective memory. A mathematical model will be used to determine how age affects the cognitive processes underlying prospective memory. The PI has validated the model and shown that the model provides a good fit to empirical data in prospective memory studies with young and older adults. Furthermore, the proposed research investigates ways to improve improve older adults' prospective memory. Ten experiments are proposed. Experiments 1-4 will examine the role of executive control in age-related differences in prospective memory. Clearly establishing the relationship between age-related differences in executive control and the processes underlying prospective memory is an essential first step. Techniques for improving prospective memory may rely on executive control and therefore may not be equally effective in young and older adults. Experiments 3-10 will evaluate different techniques for improving older adults' prospective memory. These experiments will provide a solid theoretical and empirical foundation for the extension of these compensatory techniques to non-laboratory settings in future research. The proposed research will be the first to apply formal modeling techniques to understanding how to improve older adults' prospective memory.